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A series of Al doped ZnO (ZnO : Al) films with different Al concentrations have been deposited on glass substrates using the sol-gel spin coating technique and the effect of Al concentrations on the structural, electrical, optical and photoresponse properties have been investigated. The XRD results show the presence of peaks due to the reflections of the planes from a wurtzite type of ZnO structure. The surface morphology shows that the grains become non-uniform and smaller in size as the Al doping level increases. For 1-2% Al doping, the film attains highest carrier concentration of about [?]2.7 × 1019 cm[?]3 and lowest resistivity of [?]2 × 10[?]2 O cm. The excitonic nature in the absorption spectrum disappears for doping above 1%. The band gap increases with the increase in the Al concentration. The photoconductivity studies show that although the photoresponse properties are degraded due to incorporation of Al atoms, the 1% Al doped film shows the best photoresponse properties within the doping limit up to 5%. [ABSTRACT FROM AUTHOR]

We have fabricated a ZnO nanowire (NW)/La0.65Sr0.35MnO3 (LSMO) p-n heterojunction by growing the NWs by an easy aqueous chemical route on a pressed powdered pellet of LSMO. The NWs have hexagonal wurtzite structure with good optical emission properties. The current-voltage (I-V) curves of a single NW junction measured by a scanning tunneling microscope (STM) probe show excellent rectifying behavior with rectification ratio [?]40, which is comparable to the characteristics of the junction made by large area NW array junctions. Different voltage-dependent current transport mechanisms have been found, which are explained through the use of a band diagram. [ABSTRACT FROM AUTHOR]

An activated-carbon (AC) assisted route is developed to synthesize a ZnO nanoparticle network. The route involves simple addition of AC to the solution containing the zinc salt and finally removing them by burning at higher temperature to form a sponge-like porous ZnO nanoparticles. The surface area measurements show that AC-assisted ZnO nanoparticles (AC-ZnO) have a higher surface area than those synthesized without AC (B-ZnO), which is further confirmed by the field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HRTEM) images. Ultraviolet (UV) absorbance results show that the optical quality remains almost unchanged for both types of nanoparticles. Enhanced and faster UV photosensitivity has been observed for the AC-ZnO. The change in the UV photosensing properties demonstrated here provides a new approach to synthesizing other high surface area materials for novel physical and chemical properties. [ABSTRACT FROM AUTHOR]